Overhead-boring machine



' out. 11, 1921.

R. H. HENDERSON' OVERHEAD BORING MACHINE Filed Sept. 16. 1925 IN VEN TOR.

Patented Qct. 11, 1927.

UNITED STATES PATE-NT" OFFICE..

ROBERT HALSEY HENDERSON, OF EAST ORANGE, NEW JERSEY.

y OVERHEAD-BORING MACHINE.

Application led September Thisk invention relates, generally, tovimproveinents in over-head joist boring nia-l chines; and the invention has reference, more j narticularly, to a nov-el kchain Vdriven boring machine adapted especially for heavy work involved in boring holes of relatively large diameters, e. g. from two inches upward.v

This invention has tor its principal object to provide a novel construction of heavy duty boring machine, comprising a vertical rigid support provided with a chain driven rotatable head at its upper end ln'iving a chuck for mounting large size boring bits or. angers, together with a simple and effective means, adjustable on the rigid support, tor both guiding and regulating the tension ot the drive chain, whereby the operator is enabled to most eiiiciently apply power tothe rotary head with a minimum ot eiilort, and, furthermore, whereby the ascending and descending runs ot the chain are so spread apart or separated that the operators hands, when engaging one run ot' the chain, are guarded against injurious Contact with either the support or the opposite run oi' said chain Other objects oi:` this invention, not at this time more particularly enumerated, willrbe clearly understood troni the following de- 30 tailed description of the saine.

The invention is clearly illustrated lin the' accompanying drawings, in which Figure 1 is a front elevation of thenovel heavy duty-joist boring machine, made according'to and embodying the principles oi" thisA invention; Figure 2 is a side elevation of the saine;l Figure is a transverse horihv zontal section on an enlarged scale, .taken on line 3 3 in Figure lgandlligure l is a de` tail transverse horizontal section, also on an enlarged scale, taken non line 4 4 in Figure 1., 4 l Y, y

Similar characters oflreterence are ,employed in all ot the hereinabove described views, to indicate corresponding parts.

Referring now to said drawings, the reterence character 5 indicates a rigid vertical Support in the form of an upright column or standard, preferably of tubular form. Secured to the upper end ot this support 5 is a biturcated head 6 adapted to provide a pair otl spacedv bearing arms 7, in and between which is journaled a rotatable chuck member 8.` Said chuck member 8 is adapted to receive, hold and rotate a boring bitor auger tool 9 which extends outwardly from is, 1925. serial No. 56,610.

one end thereof. `Fixed on said chuck inember ,'8, so as to be disposed between the spaced bearing arms 7, is a drive sprocket 10', which is retained against undue lateral play by the engagement of its hub between said bearing arms 7 .f Running over said drive sprocket 10lis an endless link belt or drive chain 11. Fixed on the lower extremity of said upright support 5 is afer-rule 12 having a laterally projectingboss 13. Said boss 13 is tapped and internally threaded through the ferrule 12 and wall of ithe support 5 to receive a. set-Screw 111; Telescopically fitted for slidable adjustment in the lower end ot said upright support is an extensible toot*- piece or leg 15. Said set-screw 14 serves a two-fold purpose; irst, to engage and lock,r

said foot-piece or leg 15 in desired extended position, to thus determine the desired yheight of theV support relative to the location at which the hole is to be bored; and, second, toserve as a: journal o'r` rotatably supporting a flanged idler guide-pulley 16 upon which the lower end oit' said endless linkbelt.

- sion at whichzsaid belt or chain shall run,

comprises a .transverse orlateral spreader'.

bar 17 provided at its rear side and intermediate its ends with an integrally formedrv sleeve 18which is sli'dable on said-'upright support 51 adjacent tothe lower end of the latter.r Threadedthrough the back ot said sleeve 18'is a set-screw 19, adaptedto engage the support to lock said spreader bar 17in, Said desired adjusted .s position A thereon. spreader bar 17 is provided, adjacent its're spective free endswith forwardly projectf ing journaljstuds2t). k.Journaled for treeA 'rotationon'said journal studsQO are flanged spreader pulleys 21, which respectively engage the opposite runs or courses of said belt or chain 11 as the same runs over and between the sprocket 10 and idler guide pulley 16. Connected to and between the ends of said journal studs 20, by fastening screws ,22 or other suitable fastening means, is a keeper bar 23 for retaining the spreader pulleys 21 against displacement from said journal studs.

As will be understood from an inspection of the drawings, and from the above ldescripllo tion of the parts making up my novel overhead joist boring machine, the drive belt or chain is manipulated by the operator to produce a rotary movement of the drive sprocket 10, which is inturn transmitted to the chuck member 8 and the boring bit or auger 9 carried thereby. The support 5, Ythrough a proper setting of the extensible foot piece or leg 15 connected with its lower end, having been erected to present the boring bit or aug-er 9 at the location in which the desired hole is to be bored, the operator may Vthereupon grasp the rigid support 5 by one hand so as to steady the same in working position, while his other hand is employed to pull on the belt or chain 11.. rlhe steady and eilicient application of power to the rotary chuck member and boring bit with a minimum of eiiort, particularly when boring,` holes of relatively large diameter, requires that the drive belt or chain 11 be neither too tight nor too slack; for it' the chain runs too tight, not only is undue wear on both chain and rotatable chuck of likely occurrence, but also frictional iesistance absorbs power which should be expended in driving the boring bit; on the other hand, if the chain runs too loose, not only is the smooth and even transmission of power interfered with, and possible jumping of the chain relative to the drive sprocket likely, but the slack chain is very likely to permit the operatorshand to come in contact with either the support 5 or the oppositely running course oi the chain with probable consequent injury. It is therefore desirable that provisioii should be made to enable both proper adjustment of the running tension of the chain, as well as provision adapted to: maintain properly spread apart or separated tlie respective oppositely ruiming courses ott the chain both from eachv other and respectively vfrom the support or standard 5.

In the ypresent invention both of the above Vmentioned desirable provisions are furnished i by a single simple and eliective means, cointhat the power may be transmittedV to the chuck and Vboring bit Vwith` a minimum' oi' edort, and so as to avoid undue wear and strains on the running parts.

F rom the above description it willibe evident that mypieseiit invention providesa very edicient overhead boring machine which is strong, durable, simply constructed and easily actuated, and which is especially adapt-v ed for heavy duty woiksucli as is involved in manipulating boring` bits large sizes or diameters. Y

Having thus described my invention, claiinzln an overhead boring machine, a rvertical standard having at its upper .end means toV support a rotatable boring bit chuck provided with a driving sprocket and at its lower Vend means to support an idler guide pulley, an idler guide pulley on said supporting means, said idler guide pulley being of substantially smaller diaineterthan said driving sprocket, an endless drive chain' running over and between said sprocket and guide'ppulley, a transveise'spreader bar pro-v'V vided with spreader pulleys at its oppositel ends to engage the Voppositely running courses of said chain, said spreaderbarliaving1 a hub intermediate its ends verticallyadjustable on saidistandard, andme'anstoA position said spreader4 bar. relative to said guide pulley so as to determine the desired running tension oi"I said chain between the latter ano said sprocketwvhile at-,the saine time holding theV courses oi:r said chain'outwardly spaced from*saidstandard .ln testimony' that l claiin the 'invention of relatively' Vlock said hub against movement to thus Y s et forth above l have hereunto set my hand this 12th day of Septenibei31925. i Y

ROBERT'V HALSEY HENDERSON. 

